Fix e7c3d2f on Windows

Code now relies on being able to copy struct dirents, but our Windows
emulation library used a pointer to a static buffer for the filename,
which was overwritten while iterating over the directory. Now fixed by
replacing it with a static buffer in struct dirent, as Unixes seem to.

lib/win32/emu.cpp

@@ -1130,14 +1130,9 @@ DIR *opendir(const char *name)
 		return NULL;
 	}
 
-	pDir->result.d_name = 0;
 	return pDir;
 }
 
-// this kinda makes it not thread friendly!
-// but I don't think it needs to be.
-char tempbuff[MAX_PATH];
-
 // --------------------------------------------------------------------------
 //
 // Function
@@ -1162,12 +1157,10 @@ struct dirent *readdir(DIR *dp)
 			{
 				den = &dp->result;
 				std::wstring input(dp->info.cFileName);
-				memset(tempbuff, 0, sizeof(tempbuff));
+				memset(den->d_name, 0, sizeof(den->d_name));
 				WideCharToMultiByte(CP_UTF8, 0, dp->info.cFileName, 
-					-1, &tempbuff[0], sizeof (tempbuff), 
+					-1, den->d_name, sizeof(den->d_name),
 					NULL, NULL);
-				//den->d_name = (char *)dp->info.name;
-				den->d_name = &tempbuff[0];
 				den->win_attrs = dp->info.dwFileAttributes;
 				if(dp->info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
 				{

lib/win32/emu.h

@@ -239,7 +239,7 @@ inline int strncasecmp(const char *s1, const char *s2, size_t count)
 
 struct dirent
 {
-	char *d_name;
+	char d_name[260]; // maximum filename length
 	int d_type; // emulated UNIX file attributes
 	DWORD win_attrs; // WIN32_FIND_DATA.dwFileAttributes
 };